Cylinder head retainer



Nov. 6, 1956 J. E. WITZKY CYLINDER HEAD RETAINER 2 Sheets-Sheet 1 Filed Dec. 2, 1953 INVENTOR. JUL/us E. VV/TZKY BY I W "Ill z f I M ATTORNEYS.

Nov. 6, 1956 J. E. WlTZKY CYLINDER HEAD RETAINER Filed Dec. 2, 1955 2 Sheets- Sheet 2 INVENTOR. JUL/us E. W/Tz/(Y WIIQLWIMW ATTORNEYS United States Patent O CYLINDER HEAD RETAINER Julius E. Witzky, Royal Oak, Micln, assignor to studebaker-Packard Corporation, a corporation of Michigan Application December 2, 1953, Serial No. 395,734

Claims. (Cl. 123-493) The present application relates to a cylinder head retainer for internal combustion engines and particularly to a retainer for the head-end portions of multi-cylinder diesel engines having individual type head and liner members for the respective cylinders thereof.

In the manufacture and assembly of piston-type internal combustion engines of relatively large size it is customary to cast the cylinder block, cooling jacket, and part of the crank case as a unit, providing cylindrical recesses or cylinder openings for the reception of separately formed removable cylinder liners. The cylinder liners themselves receive the reciprocating pistons therein and very obviously are subjected to great wear and are therefore made of high quality alloys; the foregoing method of construction renders the liners readily replaceable when the need for replacement arises. Although aimed at facility in repair and replacement, the provisions heretofore made for securing the cylinder liners within the cylinders of the block have not in the general case been conducive either to ease or efiiciency in removing and replacing the liners in protecting the block or cylinder parts or in insuring the clamping of the cylinder liner in place with such uniformity of pressure or force throughout its periphery as to prevent setting up uneven stresses in the assembled structure.

In my patent application Serial No. 179,493, now U. S. Patent No. 2,654,357, I have shown a novel and improved means for clamping a removable cylinder liner in place in the block of an internal combustion engine which will correct these deficiencies and obtain the desired facility, safety, and accuracy of installation. I therein disclose a 'combined head and liner member for each cylinder. In

the present application I show an improvement for clamping this combined head and liner member in place, simplifying the actual final clamping procedure to a one-man purely manual operation.

In ordinary practice the cylinder liners in engines have been secured in place through the expedient of a common cylinder head having head hold down bolts or studs which are present in great numbers requiring a corresponding great number of tightening operations and giving rise to undesirable stresses due to the lack of uniformity of the application of tightening pressure over the entire head. These current practices also create undesirable concentration of stress at the local cylinders due to the application of the tightening load at points separate and remote therefrom according to the layout of the actual cylinder head which is common to and encompasses all cylinders. The present engine, however, contemplates the provision of a single large cylindrical retaining nut threaded into the mouth of the cylinder recess or opening in the engine block casting, a plurality of separately adjustable screws carried in the periphery thereof, and an annular spacer engaging the top surface of the cylinder head. The appli cation of a uniform clamping force around the peripheral edge of the top surface of the cylinder head is a simple one-man operation accomplished by means of a tighten- 2,769,438 Patented Nov. 6, 1956 ing operation in which the stresses are transmitted from the nut to the head by means of the intermediary of the screws which directly engage the stress distributing annular spacer.

In line with the foregoing, an object of the invention 18 to provide, in conjunction with an annularly continuous nut for clamping a combined cylinder head and liner member in place, a plurality of threaded fasteners or screws in the periphery of the nut and an interposed annularly continuous spacer for distributing the separate loads of the screws and transmitting them to the combined head and liner member with uniform tightening pressure.

Another object is to provide a coacting nut and spacer which clamp a liner member in place in an assembly arrangement incorporating a crushable seal on one side of the member which permits a gap of travel to be established between the nut and spacer, the resulting gap serving as a predetermined drain gap for pools of lubricating oil which tend to collect within the confines of the spacer.

Another object of the invention is to provide a poolcollecting retainer spacer and a spaced apart retaining nut for a liner within a cylinder in an arrangement whereby an oil drain passage is formed in the wall of the cylinder adjacent the top of the final position of the spacer so as to drain off all excess oil which spills through the resulting gap in the space between the spacer and the retaining nut. According to one feature, the spacer is a short ring seated on the valve-carrying head of a liner member and a plurality of tall bottom seated valve stem cups is provided as guide extensions for the upper ends of the respective valves which pass downwardly through the head. Thus, the resulting shallow pool of oil Within the short ring will have no harmful efiect on the valve operation inasmuch as the tall inverted valve cups prevent access of unwanted oil to the valve stems.

A further object of the invention is to provide, in a cylinder head arrangement formed with valve guides surrounded by leakage-preventing cups, a short spacer member of which the periphery is annularly continuous so as to tend to collect a shallow pool of oil and adjacent to which a chamber and a passage are provided to collect and permit discharge of spilled over oil across the outside edge of the spacer.

Further features, objects, and advantages will either be specifically pointed out or become apparent when, for a better understanding of the invention, reference is made to the following written description taken in conjunction with the accompanying drawings in which,

Figures 1 and 2 are transverse elevational and plan views of an engine taken along the lines 2-2 and 1-1 of these respective figures;

Figure 3 is a plan view of a retainer part according to the invention; and

Figures 4 and 5 are fragmentary transverse elevational and plan views of a modification of the invention.

In Figures 1, 2, and 3, an internal combustion engine 19 is shown provided with preferably one but possibly more than one bank 12 each formed of a plurality of vertically disposed cylinders 14 in line with one another. The bank 12 is traversed longitudinally by a set of sinu- 0115 water cooling passages 16 which provide for the circulation of coolant for the cylinders from one end of the bank to its opposite end. At one of the lateral sides of each cylinder 14, an exhaust manifold 18 is secured as by means of a plurality of stud and nut fasteners 20, and similarly an intake manifold 22 is secured to the opposite side as by a set of fasteners 24. The exhaust manifold 18 is readily identified by a liner 26 which may be of stainless steel and which forms an annular air space 28 in order to insulate the manifold from the extreme heat of 7 of the cylinder 14Land resting on the' shoulder 70.

ieldab'le sealing ring 72'rests directly on the shoulder-'70 the internal exhaust gases therein. A conventional water jacket 30 for conducting liquid coolant [is also provided in the exhaust manifold structure 18. An opening 32 is formed in theupper end portion 3410f the cylinder 14 and municating with the loWerend-ofthe oil drain passage 36. p

Illustrative ofone example ofsuchofl ret-urn'means is a'longitudinally;extending drain passage 38 formed in the insideface of the upper flange of the intake-manifold 22'. Theintake manifold 22 has an outlet passage 49 communicating with .a supply-port oropening 42 formed in the upper end 34 of the cylinder 14. A box- 7 like longitudinal cage 44-is provided which is coextensive in length with the cylinder bank 12. A longitudinally 1 extending chamber 46 formed therein may be utilized for receiving Wiring orother conduit useful in the; operation 7 of heat gauge instruments which may be desirably fitted to the engine. Longitudinally aligned-sets of camshaft bearings such as at48 and '50 are formed'in thebox-like member 44'and each isrespectively adapted to ,receive a lobed-cam shaft such as an intake cam shaft indicated at 52 andan exhaust cam shaft indicated at '54. 'A common bearing cap 56 is secured as by a set of stud and'nut fasteners 531: the-box-lilre member 44and contains a set of sleeve-type hearings in which the cam shafts 52 ;and 54 are journalled to rotate. Each cylinder 14 in the'engine is provided Witha centrallydisposed depending fuel injector device 64) which is repetitively operated in timed sequence with respect to'ther'operatingfcycle of the engine. A cover 62 Isealed as by a cover. gasket '64 is of, identical thick-stemmed exhaust valves 98 each controlling an exhaust port 100 formed in the head and liner member 76. The exhaust port' 100 communicates with the exhaust opening 32 which registers with the exhaust passage 82w conduct exhaust gases away from the liner member 76.

The head and liner. member 76 slidably receives a reciprocating piston 102, which in its uppermost position clamped or otherwise firmly secured to the box likeimem- I oer 44 so as to cooperate therewith ini defining a central cam shaft and valve chamber 66'.

At its upper end 34 the cylinder 14 has-a set ofathreads .63 immediately inside the'mouth thereof;v at a location in spaced apart relationship withirespect to the threads 68,

the cylinder 14 has two adjacentportions of different inside diameters presenting a radially inwardly deflected annular shoulder 70. A plurality of elements may be' provided which have an applied position "within the mouth A and has a 'tongued inter-engagement-With' and sea'ling'ly supports the head or compressiontend portion 74 of an individual head andliner member 76 for the cylinder 14;

The portion 74 of the head and liner member 76 is extensively internally passaged as shown but is of a generally unitary integrated construction and-at points of fabrica tion juncture suchas' with a head closing plate 78 is welded as at 80. A valve controlled exhaust passage 82 constitutes one of the principal internal passages formed in the head portion 74 and directly communicates exhaust combustion gases to the port-32 and thence to the exhaust manifold 18. A plurality of longitudinally extending water cooling passages 84'is formed in .the'head portion 74 and also an inlet passage 86 for a combustible cylinder gas mixture is 'formed'and communicates with the supply port 42 and with the'intake manifold 22. The lowermost cooling passages 84 of Figure 1 are connected with the longitudinal block cooling passages 16 by means of the restrictively smallpassages indicated'at 88 which extend vertically upwardly through the head portion 74. 'An in- 7 take valve guide 98 cooperates with one of a pair of 7 identical thin-stemmed intake valves 92 each of which controls an intake port 94 formed in the head and liner member 76. An exhaust valve guide 96in the head portion '74 of the member-76 cooperates with one of a pair shown in solid lines inFigure 1, cooperateswith the head and liner member 76 to define an end clearance Volume chamber 154 at the upper end of the overallcombustion' 7V chamber contained within a working cylinder portion 106 of theheadand liner member 76. The .piston 102 shown by way of illustrationin'Figure 1 is adiesel piston of conventional design having :a wrist pin as at 108 and a connecting rod 110 which is attached at its lowermost end to a throw portion of an engine crank shaft, not shown. The lowermost end of the head and liner member 7 6 contains'a series of coaxial annular grooves 112 in which sealing rings as at1-14 are received forsea-ling the same to the interior surface of the cylinder 1-4. In

their applied position; each of the individual-headand' liner members 76 is readily-removable-from its-supporting' cy'iinder 14 and the s-houlder 7% upon Whichtheliner member rests. Thelclosing plate 78,- which is incorporated in the'head portion by the weld 80 previously noted at theupper'end of the head and liner member 76, supports the depending injector nozzle 69 such that the latter is concentrically arranged with respect to the vertically disposed central longitudinal axis of the cylinder 14 indicated at- 116 in Figure 2. At equally spaced-apartintervals about the axis 116 so as to define a circular path of i revolution at 118 the pair of intake and exhaust valves 92, 98 are arranged so as to be symmetrically disposed with respect to a transverse plane 312% which contains the axis 116 and is perpendicular to the general plane of the cylinders as indicatedat'122. One of a pair of diametricaliyopposed'water connections is provided at'124 which communicates withthewater coolant chambers 84 in the head portion of the member 76. The closingplate 78 7 further supports the'upper end of the respective intake and exhaust valve guides 90, 96 which' are formed as integral appendages depending from a pair of'upwardly open cup-like parts as at 126each of which telescopically receives a complementary inverted cup-like tappet part as at 128.

The aligned cylinders of the bank 14 may form only one 'of a plurality of angularly spaced banks of cylinders in the engine 19, butin-the position as hereindisclosed the bank '14 is vertically disposed-and gives the-appearance of only a single bank, line type engine. Accordingly the lower cup of each pair of telescoping parts 126, 128 extends vertically upwardly 'a predetermined distance above the upper surface of the closing plate 7.8 in the head portion 74. Thus the upper portions and mouth of the cup part 126 are considerably removed at all times from exposure to any liquids which may tend to pool or otherwise accumulate atop the closing plate '78.

The noted cup-like-parts 126g128 telescopically reciprow cate-one'within the other and mutually contain and define a valve spring chamber 1343. Within the chamber 130 a pair'of concentricvalve springs 132 is disposed so as 'to seat at the closed end of their respective associated cup-like'parts126 and thrust at their upper ends against a spring seat 134 which is locked as at 136 to the-top end of each of the stcms'of the intake and exhaust valves 92, 98. Each tappet part 128 is cam actuated as at 52; V

54so as to thrust against an interposed spacer 137 and associated valve so as to displace the" same downwardly against the resistance of thet valve return springs 132.

and open the appropriate valve controlled port in the member 76. Force-fed lubricant for the bearings of thecamshaft's '52, 54 and splash-fed lubricant for the telescoping parts 126, 123 and valve stems is supplied in abundance' and the excess portion thereof is allowed to flow by gravity down onto the upper surface of the closing plate 73 which, as previously noted, is unitarily Welded to the individual head and liner member 76. The excess oil may thus be trapped and tend to accumulate in a pool covering the closing plate 78.

Means associated with the head portion 74 may be provided for holding the same in a retained position within the upper end 34 of the cylinder '14. Illustrative of one such holding means is a centrally open ring nut assembly generally indicated at 138. An annularly continuous centrally open nut part shown at 140 in Figure 1 forms an essential element of the ring nut assembly and will be noted to have a pair of diametrically opposed internally relieved portions presenting notches at 142 best seen in Figure 3. These portions 142 permit adequate clearance between the ring nut element 140 and the water connections or fittings 124 previously discussed. A series of circumferentially spaced bolt receiving openings 144, in the aggregate amount of ten for instance, is provided in the ring nut 140 and each is tapped throughout its length for threadably receiving a hexagon headed screw 146 of a like total number in the aggregate. Each screw or bolt 146 has a smooth cylindrical shank 147 of reduced diameter at the lower end thereof. If desired an intervening stress distributing spacer ring 148 may be disposed between the closing plate 78 and the annular nut element 140 and as shown is flat sided on its opposed faces. The screw shanks 147 foot on the upper face of the spacer ring 148 and thrust thereagainst at equal circumferentially spaced intervals.

The spacer ring 148 is annularly continuous and will be noted to be relatively thin in its vertical dimension compared to the vertical depth of the upwardly open cup parts 126 whose bottoms seat on the closing plate 78.

Means may be provided for establishing a threadable engagement between the nut element 140 and the mouth of the cylinder 14. As illustrative of one form of threadable engagement means, a helical thread insert may preferably be employed in accordance with the disclosure of my previously noted Patent No. 2,654,357 but as herein shown the nut 140 has a set of external threads which directly engage the threads 68 in the cylinder 14 without the intermediary of a helical thread or heli-coil insert.

Within the mouth of the upper end 34 of the cylinder 14 below the threads 68 an annular recess 150 may be formed which communicates with the oil drain passage 36 and through which trapped lubricating oil received on the upper surface of the closing plate 78 may be conducted into the drain passage 38 and thence into the engine crank case not shown.

During assembly of the engine of Figures 1, 2 and 3, the sealing ring 70, the head and liner member 76, and the spacer ring 148 are sequentially introduced through the mouth of the open end 34 of the cylinder 14 and are lowered to a stacked position of rest against the shoulder 70 within the cylinder 14. Thereupon the screw carrying ring nut element 140 is introduced and started in the threads 68 by hand and progressively is screwed down finger tight against the interposed spacer 148 which rests directly on the closing plate 78. A seal between the latter two members may be provided at 152 and be ultimately clamped under stress therebetween to establish a fluid-tight sealed relationship in the manner hereinafter specified. Through use of an appropriate hexagonal socketed tool, the individual bolts or screws 146 are brought down tight in equalized stages so as to press against the upper face of the stress distributing spacer ring 148 and preload the nut element against turning in the threads 65 with which the nut element 140 is engaged. As the yieldable seal 70 begins to crush somewhat under the resulting progressive pressure, a separating action occurs between the stress distributing spacer ring 148 and the threaded nut element 140 so as to form an intervening gap of predetermined clearance at 154. This gap at 154 has the function of completing a path of communication leading from any pool or accumulation of lubricating oil confined by the spacer ring 148 and the closing plate 78, thence over the upper face of the spacer ring 148 and between the shanks 147 of the spaced apart screws 146, thence across the outside upper edge of the spacer ring 148, and finally through the annular recess 150 and the downwardly directed oil drain passage 36. Increased tension imparted to the screws 146 places the head portion 74 under considerable compression and forms a gas-tight and fluid-tight seal both at 72 and 152. Subsequent explosions in the clearance volume chamber 104 due to engine operation force the piston 102 to be driven downwardly without the escape of any explosion gas upwardly from the working cylinder 106. The upward pressure on the bottom side of the head member 74 is readily opposed due to the non-rotatable reaction of the pre-loaded nut member against turning and backing out of the threads 68 formed in the upper end of the cylinder 14.

In the modified showing of Figures 4 and 5, a cylinder 214 is provided an upper end portion 234 which has a set of internal threads 268 immediately inside the mouth thereof to receive a threaded ring nut element 240 similar to the element 140 of the preceding embodiment. The tension screws which are indicated at 246 and of a number of approximately ten, are of the Allen wrench type, so-called, and have an internal hexagonal opening as at 248 for receiving an Allen bar or wrench to adjust and tighten the same. The screws 246 are received in suitable threaded bores of a like number in the ring nut element 249 and have smooth cylindrical shanks 247 of reduced diameter which engage a flat topped stress distributing spacer ring 249 having a frusto conical lower surface 250. A companion frusto conical surface is formed on a closing plate 273 which is welded at a juncture 286 to an individual head and liner assembly 276. An interposed seal at 252 is clamped between the closing plate 278 and the frusto conical spacer ring 249. The ring 249 is relatively thin in its vertical dimension similarly to the preceding spacer ring 148. The head and liner member 276 slidably receives a diesel piston 202 and therewith defines an end clearance volume chamber indicated at 204, the piston 292 being shown in solid lines in its uppermost position of reciprocation. A yieldable sealing ring 272 of deformable material has tongued interengagement with and supports the head portion of the member 276 in compression and rests on an annular shoulder 270 formed by dissimilar diametered interior portions within the cylinder 214. A conventional water passage as at 216 is provided between the liner portion of the member 276 and the cylinder 214. A set of block anchored, cam shaft bearing hold-down bolts may be provided as at 258.

In the embodiments of Figures 1 and 4 it will be noted that the head or compression portion of the respective members 76, 276 has substantially the same outside diameter as the diameter of the retainer nut 40, 240 and substantially the same diameter as the inside diameter of the retainer nut threads 68, 263 formed at the mouth of the upper ends 234, 34 of the cylinders. Thus, essentially all elements retained in the cylinders in their applied position are within the confines of the cylinder and the selected diameter at the mouth of the cylinder is, in most respects, a minimum size compared to the overall cylinder dimensions. The self-confinement that results within the'closed-ended cylinder yields a highly satisfactory and stiff engine structure requiring no excessive spacing between cylinders and permitting a multicylinder engine of relatively short axial length to be constructed. The stage by stage tightening operation of the screws 146, 246 in the embodiments of Figures 1 and 4 is essentially a one-man operation and no undue amount of torque is required at any one time in order progressively to precompress the head and its supporting seal and place a considerable amount of preloading on the internal 77 a cylinder threads whichthe respective retainer nuts 68, 268 engage. Removal of the head is likewisea simple operation requiring merely the progressive stages of un-' screwing the threaded fasteners 146, 246 in any of a Reducing "the tension of such fasteners may result in some cases 'in the disappearance of a considerable portion of the number of predetermined known sequences.

clearance gap 154- but enough clearance is inherently retained due to permanent deformation of the seals 70, 270

such that at all times during disassembly there will be adequate clearance'betweenthe ring nuts 14%, 240 and their associated structures to permit unscrewing of the nuts simply by hand.

The principal advantage of the frusto conical surface 7, -250 shown in the embodiment of Figure 4, is that it may permit a slightly discernibleself-centering action of the -spacer 249 to occur during the'prestressing of the compression head of the liner member 276, it being understood that design tolerances between the outside circumference of the spacer ring 249 and the inside circumference of the companion portion of the cylinder 234 may result in a slight lateral clearance occurring therebetween Thus the 7 under the variable conditions of manufacture.

ring 249 may tend'to shift. somewhat in its own plane as it is progressively drawn down against the frusto-conical surface 250 on the head closing plate 278 In the clamping arrangements herein disclosed, each retainer nut for the cylinder heads is threaded inside the individualengine cylinder at the upper outer end thereof. It is evident that in many readily conceived applications not limited to engine-type cylinders, the present clamping arrangement may be used to advantage where the nut and its associated compression member are disposed on the outside of a threaded cylinder and the nut is inter'nally threaded and disposed at the outer end of the cylinder in threaded engagement with external threads on the cylinder. So also the drawing shows opposed engageable transverse surfaces formed on the nut and cylinder members between which the compression member is it is desirably the case that the crushable seal will be at s and each including a first member internally received in the one end of one cylinder, said first member having an upper area exposed to the impingement of leaked oil subject to'accumulation in a pool thereupon and having a lowerportion disposed adjacent said shoulder portion and together having a seal clamped therebetween, valve guide means including an upstanding cup-like part seatedon a portion of the aforesaid upper area of the first member with the walls thereof extending a predetermined distance vertically upwardly, a second member in threaded engagement with said threaded portion in closely spaced adjacency to the first member, and means acting between the two said members under prestress including a ring member having one face against which the nut member is initially screwed finger tight within said threaded portion and having another face seated on'said head member so as to encircle said upper area in surrounding relation to said cup-like part, said ring member having a depth of thickness of a dimension less than the dimension of said predetermined distance such that the level of said one face is below the upper portion of the walls of the cuplike part, and a plurality of separately adjustable elements all carried by the nut member and finally preloaded so as 'the depth of the pool to a value less than enough to immerse the upper portion of the walls of the cup-like part.

3. In a m'ulti-cylinder engine each cylinder of which is adapted to receive a central liner and is provided with spaced apart shoulder and threaded portions inside one end of the cylinder, means individual to said cylinders and each including a head member internally received in the one end of one cyinder, said head member having an upper area exposed to the impingement of leaked oil subject to accumulation in a pool thereupon and having a J lower portion disposed adjacent said shoulder portion and oneside of the compression member and the spacer ring spaced apart shoulder and threaded portions inside one end of the cylinder, means individual to said cylinders .and each including a first member internally received in the one end of one cylinder, said first member being dis-. posed adjacent said shoulder portion and having a seal clamped therebetween, a second member in threaded en gagement with said threaded portion in closely spaced adjacency to the first member, and means for separating said members under prestressed conditions so as to crush said seal against leakage and preload the engagedthreads against turning including 'a plurality of separately ad-. justable elements all carried by one of the members.

2. In a multi-cylinderengine each cylinder. of which is adapted to receive a central liner and is provided with spaced apart shoulder and threaded portions inside one end ofthe cylinder, means individual to said cylinders.

together having a seal clamped therebetween, valve guide means including an upstanding cup-like part seated on a portion of the aforesaid upper area of the head member with the cup walls extending a predetermined distance vertically upwardly, a centrally open nut member in threaded engagement with said threaded portion in closely tight within said threaded portion so as to encircle said upper area in surrounding relation to said cup-like part, said ring member having a depth of thickness of a dimension less than the dimension of said predetermined distance such that the level of said one face is below the upper portion of the walls of the cup-like part, there being a drain passage formed in said threaded portion adjacent the normal position of the bottom of said nut, and a plurality of separately adjustable elements all carried by one of the members and finally preloaded so as to press against the opposite one of the members and separate the same with a resulting predetermined clearance gap which is in continuous communication with said tions inside one end of the cylinder, means invidiual to drain passage. I a

4. -In a multi-cylinder engine each cylinder of which is provided with spaced apart shoulder and threaded porsaid cylinders and each including an internally received head member in the space in the one end ofthe cylinder between the shoulder and threaded portions and supported .by the shoulder portion, a nut member in threaded engagement with said threaded portion in closely spaced 'adjacency to the head'member, said members being of substantially the same order of outside diameters, and

mela'ns. for separating said members under prestress so as to preload said engaged threads against turning of the nut member including a ring having a first face seated on said head member, and a plurality of separately adjustable circumferentially spaced apart elements all carried by the nut member as its pro-loading devices and pressing against a second face on the ring.

5. In a piston engine, an elongated cylinder Within which a multiplicity of members is applied in position for reciprocally receiving and power driving a piston, and including an individual head and liner member supported in the cylinder, a ring member adapted to seat thereon, and a seal member efiective to be clamped between the head and ring members, and means for securing the members in applied position including similar supported first parts separately adjustably engageable with the ring member and a supporting second part for the first parts and threadably engaged thereto, md to the interior surface of said cylinder, there being an oil drain passage formed in said cylinder adjacent the bottom of the last named means, said second part comprising an open centered nut member initially adjusted in finger tight threaded engagement against the ring member, said first parts subsequent thereto being prestressed into engagement with the ring member so as to separate the nut and ring members with a predetermined clearance gap establishing constant co 1-- munication with said oil drain passage.

6. A piston engine including a generally cylindrical part having a hollow interior within which a multiplicity of members is applied in position for reciprocally receiving and power operating a piston and including an individual head and liner member supported in the cylindrical part, a ring member adapted to seat thereon, and means for securing the members in applied position including similar supported first parts separately adjustably engageable with the ring member and a supporting second part for the first parts disposed in closely spaced adjacency to the ring member and threadably engaged with the first parts and with the interior surface of said cylindrical part in pro-loaded condition against turning of the latter part.

7. In combination, a generally elongated supported hollow element, a nut element in threaded engagement therewith at the outer end of the hollow element, said hollow element having a transverse inner surface facing toward the counterpart transverse inner surface of the nut element, a ring-like part juxtaposed to each inner surface, at least one of the ring-like parts comprising a yieldable member and disposed in axially spaced apart relationship with respect to the other part, a compression member disposed in the space between the ring-like parts and adapted to be initially clamped thereby when the nut is rotated down finger tight against the juxtaposed ringlike part in its threaded engagement with the hollow element, and means for predeterminedly preloading the compression member including a plurality of threaded elements protruding through the transverse inner surface of one of the elements and separately adjustably engageable with the adjacent ring-like part.

8. In combination, a generally elongated supported hollow element, a nut element in threaded engagement therewith at the outer end ofthe hollow element, said hollow element having a transverse inner surface facing toward a counterpart transverse inner surface of the nut element, a ring-like part juxtaposed to each inner surface and axially spaced apart with respect to the other ring-like part, a compression member disposed in the space between the ring-like parts and adapted to be initially clamped thereby when the nut element is rotated down finger tight in its threaded engagement with the hollow element, and a plurality of screw fasteners individually adjustably carried by one of the elements and protruding through the transverse inner surface thereof into engagement with the adjacent ring-like part, the justsaid part comprising a rigid spacer ring for transmitting a compression preload from the screw fasteners to the compression member.

9. In combination, a generally elongated supported hollow element, open centered nut element in threaded engagement therewith at the outer end of the hollow element said hollow element having a transverse surface which is inwardly opposite from a counterpart transverse surface of the nut element, a first ring-like part comprising a rigid open centered spacer at the outer end of the hollow element in juxtaposition to the transverse surface of the nut element, a second ring-like part comprising a yieldable seal juxtaposed to the transverse surface of the hollow element, said first and second parts being disposed in axially spaced apart relationship with respect to one another, a compression member disposed in the space between the ring-like parts and adapted to be initially clamped thereby when the nut element is drawn down finger tight in its threaded engagement with the outer end of the hollow element, and a plurality of tool-adjusted threaded elements carried by the nut element in a manner to protrude through the transverse surface thereof into engagement with the rigid spacer for precompressing the compression member.

10. In a multi-cylinder internal combustion engine each cylinder of which is adapted to receive a central liner and is provided with spaced apart shoulder and threaded portions inside one end of the cylinder, means individual to said cylinders and each including a head member internally received in the one end of one cylinder, said head member having an upper area exposed to the accumulation of leaked oil in a pool thereupon, and having a lower portion disposed adjacent said shoulder portion and together having a seal clamped therebetween, valve guide means including an upstanding cup-like part seated on a portion of the aforesaid upper area of the head member with the cup walls extending a predetermined distance vertically upwardly, a centrally open nut member in threaded engagement with said threaded portion in closely spaced adjacency to the head member, and means acting between the head and centrally open nut members under prestress including a ring member having one face seated on said head member and an opposite face against which the bottom of the nut member is initially screwed finger tight within said threaded portion so as to encircle said upper area in surrounding relation to said cup-like part, said ring member having a depth of thickness of a dimension less than the dimension of said predetermined distance such that the level of said one face thereof is below the upper portion of the walls of the cuplike part, there being a chamber forming annular recess formed in said threaded portion adjacent the normal position of the bottom of said nut and having a drain port formed adjacent thereto and communicatively connected therewith, and a plurality of separately adjustable elements carried by one of the members and finally preloaded so as to press against the opposite one of the members and separate the same with a resulting predetermined clearance gap forming an oil escape path across an edge of said one face of the ring member for conducting away a flow of excess oil from said pool so as to limit the depth of the pool to a value less than enough to immerse the upper portion of the walls of the cup-like part, said oil escape path intersecting said drain port connected chamber.

References Cited in the file of this patent UNITED STATES PATENTS 1,678,946 Joyce July 31, 1928 2,155,180 Caldwell Apr. 18, 1939 2,282,502 Suth May 12, 1942 2,349,170 Jackman May 16, 1944 2,424,449 Gasche July 22, 1947 2,563,949 Magnuson Aug. 14, 1951 2,595,592 Magnuson May 6, 1952 2,650,868 Waldron Sept. 1, 1953 2,654,357 Witzky Oct. 6, 1953 

